"The response to natural disasters brings out the best and worst in people," U.S. Attorney Tim Johnson said in a statement. "Generous acts of charity are tarnished by those who despite the generosity of others, fraudulently make claims for government relief funds."

Darlene McGruder Poole, 30, of Houston, and her sister, Lashona McGruder Victor, 37, of La Place, La., are charged together with conspiracy to commit mail and wire fraud, according to the U.S. attorney's office in Houston.

Kiesha Murphy, 34, of Houston, and Angela Payne, aka Angela McKinnies, 38, of Houston, are charged separately with theft of government property and making false statements to the Federal Emergency Management Agency.

Indictments against the four women were returned Aug. 12 and unsealed Wednesday.

One alleges Poole submitted declarations of need for continued rental assistance after her August 2006 purchase of an Angel Lane home. Victor, meanwhile, registered with FEMA as Poole's landlord and submitted fraudulent lease agreements and rental receipts, prosecutors charge.

Murphy and Payne are accused in the other two indictments of submitting fraudulent claims for rental assistance after buying Angel Lane homes in July 2006.

Murphy declined to comment when reached by telephone Wednesday. Calls to Poole and Victor rang unanswered. A listing for an Angela McKinnies was disconnected and there was no listing for an Angela Payne.

Oprah Winfrey's charity partnered with Habitat for Humanity to build and furnish homes for approximately 65 families forced to relocate to Houston as a result of Hurricanes Katrina and Rita in 2005. The Angel Lane Housing Development allowed displaced individuals to purchase new homes under extremely favorable financing terms.

Telephone and e-mail messages were left late Wednesday for Winfrey representatives.

Victor and Poole each face up to 20 years in prison and a $250,000 fine if convicted. Murphy and Payne each face up to five years on the false statement charges, up to 10 years for theft of government property and a fine of up to $250,000 if convicted.